fs: dlm: handle non blocked connect event

The manpage of connect shows that in non blocked mode a writeability
indicates successful connection event. This patch is handling this event
inside the writeability callback. In case of SCTP we use blocking
connect functionality which indicates a successful connect when the
function returns with a successful return value.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lowcomms.c

@@ -78,6 +78,7 @@ struct connection {
 #define CF_APP_LIMITED 7
 #define CF_CLOSING 8
 #define CF_SHUTDOWN 9
+#define CF_CONNECTED 10
 	struct list_head writequeue;  /* List of outgoing writequeue_entries */
 	spinlock_t writequeue_lock;
 	int (*rx_action) (struct connection *);	/* What to do when active */
@@ -419,6 +420,12 @@ static void lowcomms_write_space(struct sock *sk)
 	if (!con)
 		goto out;
 
+	if (!test_and_set_bit(CF_CONNECTED, &con->flags)) {
+		log_print("successful connected to node %d", con->nodeid);
+		queue_work(send_workqueue, &con->swork);
+		goto out;
+	}
+
 	clear_bit(SOCK_NOSPACE, &con->sock->flags);
 
 	if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
@@ -604,6 +611,7 @@ static void close_connection(struct connection *con, bool and_other,
 
 	con->rx_leftover = 0;
 	con->retries = 0;
+	clear_bit(CF_CONNECTED, &con->flags);
 	mutex_unlock(&con->sock_mutex);
 	clear_bit(CF_CLOSING, &con->flags);
 }
@@ -1027,8 +1035,11 @@ static void sctp_connect_to_sock(struct connection *con)
 
 	if (result == -EINPROGRESS)
 		result = 0;
-	if (result == 0)
+	if (result == 0) {
+		if (!test_and_set_bit(CF_CONNECTED, &con->flags))
+			log_print("successful connected to node %d", con->nodeid);
 		goto out;
+	}
 
 bind_err:
 	con->sock = NULL;